Adhesive patches are known which contain tulobuterol as a selective stimulant of sympathetic nerve β2 receptors in a pressure-sensitive adhesive layer composed mainly of a synthetic rubber-based pressure-sensitive adhesive (for example, see Patent document 1). There are also known adhesive patches containing tulobuterol in a pressure-sensitive adhesive layer composed mainly of an acrylic-based pressure-sensitive adhesive (for example, see Patent document 2).
In an adhesive patch containing tulobuterol in a synthetic rubber-based pressure-sensitive adhesive where the crystals of tulobuterol are dispersed in the pressure-sensitive adhesive layer, sustained release of the tulobuterol from the pressure-sensitive layer is therefore achieved, yet not without problems such as poor start in release and inadequate release amount. Also, while the start in release is improved with an adhesive patch employing an acrylic-based pressure-sensitive adhesive, the lack of sustained release is a problem.
In other words, pressure-sensitive adhesives used in conventional tulobuterol adhesive patches have poor compatibility with the drug and additives, such that the drug must be added in an amount above the saturation concentration and deposition of crystals of the drug in the pressure-sensitive adhesive layer can occur, possibly resulting in unsatisfactory drug release and adhesion to skin.
There are also known pressure-sensitive adhesives wherein a copolymer obtained by copolymerizing acetoacetoxyalkyl (meth)acrylate and another vinyl monomer is crosslinked using a polyamine compound or isocyanate compound (for example, see Patent documents 3 and 4). However, no literature can be found describing an adhesive patch obtained by adding a percutaneously absorbing drug to an acrylic-based pressure-sensitive adhesive layer composed of a copolymer comprising acetoacetoxyalkyl (meth)acrylate as one of the constituent monomers.
[Patent document 1] WO97/14411
[Patent document 2] Japanese Unexamined Patent Publication HEI No. 11-228395
[Patent document 3] Japanese Unexamined Patent Publication HEI No. 6-108033
[Patent document 4] Japanese Unexamined Patent Publication HEI No. 7-238203